Iceberg Order

In simple terms

Imagine you want to buy a huge amount of something at a store, but you're worried that asking for it all at once will make the price jump up. So instead, you buy it in smaller chunks at different times to keep the price stable. An iceberg order works the same way—a trader breaks up a giant buy or sell order into smaller pieces so the market doesn't react and move against them.

Definition

Large order split into smaller visible orders to avoid moving the market.

In depth

An iceberg order is an execution strategy where a large order is fragmented into multiple smaller visible tranches, with only one tranche displayed to the order book at a time while the remaining quantity remains hidden. As each visible portion is filled, the system automatically replenishes the visible quantity from the hidden reserve, creating the illusion of sustained demand or supply at a specific price level. This technique minimizes market impact and information leakage, preventing adverse price movement that would typically occur if the full order size were immediately visible to other market participants. The mechanism relies on exchange systems that support hidden or reserve order functionality, allowing traders to conceal their true intent and total position size during execution.

How does Iceberg Order work?

You submit one large order but specify a smaller visible quantity. The exchange displays only that visible slice in the public order book and keeps the remainder hidden. When the visible slice fills, the matching engine automatically replenishes it from the hidden reserve and posts a new slice, repeating until the full amount is filled or you cancel. To anyone reading the book, a series of modest orders appears rather than one large one. Refreshed slices usually lose queue priority, so an iceberg can fill more slowly than a fully displayed order.

An example

Illustrative figures only. A fund wants to buy 500 units and posts an iceberg with a 20-unit visible size at a limit of $40. The book shows 20 units at $40. As sellers hit it, that slice fills and a fresh 20 units appears, then another, and so on. Twenty-five refills are needed to complete 500 units. Observers see steady small demand rather than a single 500-unit order.

Figures are illustrative only.

What beginners get wrong

• Iceberg orders hide size from the book but not from the exchange, and repeated same-size refills at one price are a recognisable pattern.
• Support for icebergs and the minimum visible size vary by venue, so an order valid on one exchange may be rejected on another.
• Hidden portions often pay taker rather than maker fees on some venues, quietly raising the cost of the whole order.
• Retail-sized orders rarely move a market enough to need hiding, so the added complexity usually buys nothing at small size.

Related terms

• Depth of Market
• Order Flow
• Limit Order
• Whale
• Dark Pool
• Slippage

Part of

What do the different crypto order types do? — the subject page for order types, with all 9 of its definitions in one place.